共查询到20条相似文献,搜索用时 0 毫秒
1.
高动态多普勒频率估计及其Cramer-Rao界 总被引:2,自引:0,他引:2
用泰勒级数展开的形式表示高动态的多普勒频率参数,推导分析了对各阶频率参数估计的最大似然估计器(MLE)及其估计误差的Cramer Rao界;描述了最大似然估计器和扩展卡尔曼滤波器(EKF) 对各阶频率参数的估计模型;并以均方根估计误差和失锁概率为性能指标,通过对同一模拟的接收机高动态轨迹的跟踪估计,比较了两种不同估计技术的基本性能。 相似文献
2.
3.
4.
5.
提出了考虑组织气化温度动态变化的选择性光热解(SP)光热作用新模型,模型包括模拟激光能量在组织内分布规律的基于网格的三维Monte Carlo模拟方法,计算组织内温度分布的考虑组织热物性参数和气化温度动态变化的三维Pennes生物传热方程,以及计算组织热损伤程度的Arrhenius方程3个部分.研究表明,滞留水蒸气系数k对结果有很大影响.k=0,0.022,0.18和1时的动态气化温度SP模型的数值结果分别接近于恒定100℃气化温度SP模型、恒定110℃气化温度SP模型、恒定130℃气化温度SP模型和不考虑气化影响的SP模型. 相似文献
6.
7.
8.
9.
10.
《Microwave Theory and Techniques》2009,57(7):1753-1759
11.
12.
13.
该文讨论了全连接结构的光交换网络在Hose不确定模型下的动态选路问题,并基于Valiant负载平衡机制,提出了一种新的动态选路算法.分配系数可调的负载平衡选路算法(Load Balancing with Adjustable Distribution Fraction, LBADF)。LBADF算法根据网络中各条链路上空闲光路的数目对Valiant负载平衡机制中的分配系数进行动态的调整,从而达到优化网络性能的目的。计算机仿真表明LBADF算法相对于分配系数恒定的VLB算法具有更小的全网呼损率,同时也相应地降低了全网中所有节点对的最大呼损率。 相似文献
14.
15.
16.
Multimedia decoding is one of the key parts of many popular mobile multimedia applications, such as video telephony, streaming, and video playback. Since the multimedia decoding consumes a significant amount of energy on processors, it is crucial to lower the power consumption and prolong the battery life. In this paper, the statistical analysis of more than 600 processor load trace files is first presented. From the analysis, we found that it is feasible to predict the processor load of multimedia applications accurately using a low order linear time series model if the load is sampled using the feature period, which is obtained with fast Fourier transformation. Based on the analysis, we propose a novel interval-based DVS scheme to achieve penalty controllable energy reduction. The DVS scheme does not need any task profile or involvement of application program, and it is compatible with the service model of general purpose mobile operating systems. In addition, the proposed DVS scheme can handle the nonstationary behavior using an efficient online change detector, and important parameters, such as coefficients of the linear time series model, are estimated on the fly. More importantly, the proposed scheme can keep the overscaling rate (OSR) around a certain predefined value. Since the OSR has a simple and stable relationship with the deadline miss rate (DMR), the penalty incurred by DVS is effectively controlled. Experimental results show that the proposed DVS scheme achieves a much smaller prediction error than previous approaches and achieves a significant processor energy reduction with adjustable and controlled penalty 相似文献
17.
提出了一种新颖的对数城电流模式积分器。该积分器的时间常数由参考偏置电流控制。用该积分器设计了二阶带通滤波器和0.1dB纹波三阶Chebyshev低通滤波器。计算机仿真表明,所设计的滤波器实际频响特性几乎是理想的,而且高频谐波失真很小,通频带灵敏度很低,频率在很宽的范围内可控。电路由双极型晶体管和接地电容构成,适合于全集成实现。 相似文献
18.
19.
Frequency-domain (FD) adaptive filter algorithms are able to achieve a low computational complexity by using the overlap-and-save implementation means compared to time-domain (TD) ones. In this article, we propose a new FD least-mean-square (FD-LMS) algorithm which dynamically selects frequency bins in order to reduce the computational complexity and maintain the convergence performance of the conventional FD-LMS. The optimal selection of frequency bins is derived by the largest decrease between the successive FD mean square deviations (MSDs) at every data block. Simulation results show that the proposed algorithm provides a low steady-state normalized MSD (NMSD) and similar convergence rate compared to the conventional FD-LMS algorithm. In addition, it gains a low computational complexity. 相似文献